Ext.onReady(function() {
			var root = new Ext.tree.AsyncTreeNode({
						id : "root",
						text : "树的根"
					});
			var tree = new Ext.tree.TreePanel({
						renderTo : "hello",
						root : root,
						loader : new Ext.tree.TreeLoader({
									url : "js/demo/treedata0904.js"
								}),
						width : 100
					});
		});